Microcosmic salt (see infobox for systematic names) is a salt found in urine with the formula Na(NH4)HPO4. It is left behind in the residues after extracting the urea from dried urine crystals with alcohol. In the mineral form, microcosmic salt is called stercorite.

Microcosmic salt[1]
Names
IUPAC name
Ammonium sodium phosphate
Other names
Microcosmic salt, ammonium sodium hydrogen phosphate or phosphorsalz
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.128.899 Edit this at Wikidata
EC Number
  • 250-787-1
UNII
  • InChI=1S/H3N.Na.H3O4P/c;;1-5(2,3)4/h1H3;;(H3,1,2,3,4)/q;+1;/p-1 ☒N
    Key: CUXQLKLUPGTTKL-UHFFFAOYSA-M ☒N
  • InChI=1/H3N.Na.H3O4P/c;;1-5(2,3)4/h1H3;;(H3,1,2,3,4)/q;+1;/p-1
    Key: CUXQLKLUPGTTKL-REWHXWOFAM
  • [NH4+].OP(=O)([O-])[O-].[Na+]
Properties
Na(NH4)HPO4
Molar mass 137.0077 g/mol
Appearance odorless crystals
Density 1.544 g/cm3
Melting point 80 °C (176 °F; 353 K)
5 parts cold, 1 part boiling water. Practically insoluble in ethanol
Structure
Monoclinic
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Its name was coined in Latin (sal microcosmicum) by Paracelsus in the 16th century, but it was also referenced by Pseudo-Geber in the late Middle Ages; another alchemical name for it was sal urinae fixum (as opposed to sal urinae volatile).[2] The first extraction of pure phosphorus came from this salt in the 17th century, when Hennig Brandt attempted to extract gold from urine.

Microcosmic salt is used in the laboratory as an essential ingredient of the microcosmic salt bead test for identification of metallic radicals on the basis of the color they produce in oxidising or reducing flame, in hot or cold condition.

Microcosmic salts form a tetrahydrate.

References

edit
  1. ^ "572. Ammonium Sodium Phosphate". The Merck Index (10th ed.). Merck and Co. Inc. 1983. pp. 80. ISBN 0-911910-27-1.
  2. ^ Mellor, Joseph William (1922). Supplement to Mellor's Comprehensive Treatise on Inorganic and Theoretical Chemistry: suppl. 3. K, Rb, Cs, Fr. Longmans, Green and Company.